NO... Reforgelite is not about stat weights, neither are any reforges, you have a priority based on stat weights, but once you know that f.ex mastery>haste>crit(arcane) then its a matter of priority, 160 for mastery, 140 for haste, 120 for crit. Then use the Cap functions in reforgelite if you need any capped stats. In the case of arcane you should set a haste cap in the drop box below the Hit cap option.
choose "haste" in first drop box. Choose "at least" in the next. "manual" in third. Then you have 2 boxes you need to fill with numbers, the first one is the cap you want(3057 in the case of mastery arcane) the next one is the value reforgelite will give after you reached that cap, in this case it should be set to 140, as haste is still better than crit(120) after cap.

Originally Posted by Dragon9870

ReforgeLite does make a few mistakes, but if you're smart enough to catch them and put in your own weights/priorities, you're fine.

I learned this recently about Fire when I went to reforge on the PTR. It said the priority was Crit Mastery Haste .-.;

personally ive never experienced any mistakes, and what you experienced is not a mistake either. in tier14 BiS and maybe even before that, the fire prio is crit>master>haste. on lower iLvls its true that fire prio is crit>haste>mastery, but reforgelite standard options is for BiS.

Like i said earlier, reforgelite only fails if people dont set it up properly according to their own priority as a result of their stat weights.

thanks - im in a situation where i have about 2700 haste. due to gear reforges (and maintaining a healthy hit cap of 15%) I am short of the 3057 cap by a little over 300. However, I have used the prismatic socket in my weapon and put 320 mastery in it due to arcane. Will the loss of 320 mastery in that prismatic socket be worth it to put 320 haste in it so i can get the extra dot tick on LB/NT?

Tbh if you are that low on gear, you should not be going mastery arcane any way. Just go full haste arcane.
If you want to stick with mastery any way, i would suggest getting the NT breakpoint if its only sacrificing 300 mastery.

From personal testing haste arcane was superior to mastery arcane until i was able to get 8k++ mastery. Though dont take my answer as an absolute truth =)